1. Field of the Invention
The present invention generally relates to foldable shipping containers and, more particularly, to an intermediate bulk container (IBC) in which the outer container or shell is foldable and reusable. Containers according to the principles of the present invention are particularly suitable for the transportation, storage and handling of flowable materials, such as liquids and flowable powders, and generally have a capacity of at least two hundred and seventy-five (275) gallons.
2. Description of the Prior Art
Numerous industries require the transportation and storage of bulk flowable materials (hereinafter liquids). While a variety of containers are presently used, one of the most common continues to be the conventional fifty-five (55) gallon drum. The disadvantages of these cylindrical drums have been well documented and include, without limitation, the following: an inefficient use of storage space, an inefficient use of transportation space, difficult handling, difficult content discharge, and inconvenient reuse and disposal of empty drums.
Because of the inefficiency in returning the empty drums, the drums themselves are generally regarded as disposable items which, in the past, have been largely discarded. Aside from the obvious volume of landfill space uselessly occupied by such drums, this also gives rise to environmental concerns which result from the residual materials located in the drums migrating into the leachate of the landfill.
Reusing the drums has its own set of problems. In particular, the necessary complete emptying and cleaning of the drums requires expensive machinery. Transporting the empty drums back to the liquid supplier further constitutes an extremely inefficient use of transportation space because of the large "empty" volume being transported.
More recently, the fifty-five gallon drum has been replaced by larger quantity, cubic shaped shipping containers. These containers not only provide for enhanced stacking and handling, but also provide benefits with respect to disposal, reusability and conservation of shipping space. Unlike cylindrical drums, cubic containers are capable of occupying substantially all of the space within the shipping vehicle.
One variety of cubic shipping container includes a box-like outer jacket or shell in which is contained a blow molded, polyethylene inner tank. Since the shell never directly contacts the liquids being transported, contamination of the outer shell is not a concern and the inner tank is easily removed before recycling or reuse of the outer shell. The used inner tank itself can either be disposed of or recycled.
In an attempt to improve upon the reusable IBC, containers have recently appeared in which the outer shell is foldable into a collapsed state. This allows the container to be shipped from the container manufacturer to the liquid supplier in a reduced size configuration which permits an increased number of containers to be shipped in the same or decreased amount of space. At the liquid supplier's facilities, the shell is unfolded or erected, the inner tank is filled, and the container shipped to the end user. Once the contents have been emptied from the container, the outer shell can again be folded and sent back to the material supplier for reuse, either with or without the inner tank.
Some foldable IBCs have been seen where the base of the container is in the form of a pallet with the side and top walls provided in a loose manner for later assembly. One disadvantage of this type of IBC is that separate, loose components increase the likelihood that a component of one container might be lost, misused or mixed with the components of another container. Additionally, the time and effort required to assemble such a container is intensive and, accordingly, expensive.
Other foldable containers have been seen where the base, sidewalls and top wall are all connected together. This type of construction avoids the problems of losing individual components of a specific container. However, when folding these containers, a specific folding procedure, which is not always readily apparent from the appearance of the container, must be followed to ensure that the container will fold and its maximum size reduction is achieved. Additionally, because of these specific folding procedures, the actual dimensions of the container's sidewalls, as well as the base and the top wall, are often dictated by the construction itself. One often seen consequence of this is that, when folded, the walls do not lay parallel to the base. Rather, the walls lie in an inclined state which makes stacking of multiple folded containers difficult and potentially unsafe.
Another problem with IBCs in general relates to the filling of the inner tank. In a foldable IBC, the inner tank is often provided to the liquid supplier in a collapsed condition within the folded shell itself. When attempting to fill a collapsed container, difficulties arise in accessing the container and ensuring that all air contained therein is properly evacuated as the container fills and assumes its uncollapsed shape.
One way of trying to avoid the problems associated with filling a collapsed tank is to provide a bridge across the top of the erected outer shell and suspending the inner tank from the bridge so as to support the collapsed inner container during filling. Another method is to inflate the inner container with air prior to filling. As the inflated container is filled with the liquid, the air within the inner container is evacuated in a controlled manner.
Problems arise with both of the above systems because of the awkwardness with which the collapsed inner tank is accessed after the outer shell has been erected. The size of the IBC itself makes leaning over the sides of the outer shell, in order to grasp the inner container for inflation or connecting to the bridge, a difficult and strenuous procedure.
Yet another limitation of prior IBCs relates to the valve assembly generally used with these containers. Typically, these containers are provided with an integral discharge nipple or fitting which is obstructed by a web or wall that has been unitarily formed in the nipple during blow molding of the inner tank itself. Once a filled IBC is received by the end user, a valve assembly, provided separate from the IBC, is threaded onto the end of the nipple. This valve assembly is provided with an integral knife that will pierce the web obstructing the passageway. However, the web is not completely removed and a portion of it remains unitarily connected to the nipple to prevent it from occluding the outlet. Once attached, the valve assembly extends outward beyond the exterior of the IBC.
Obviously, an IBC could not be shipped with the valve extending beyond its side walls because of potential damage to the valve. An additional problem with this construction is that the end user must keep a supply of separate valve assemblies on hand for use with the IBCs. Another problem specifically relates to the piercing of the web and discharge nipple. As a result of the web not being completely removed from the interior of the discharge nipple, partial obstruction of the discharge passageway occurs and some amount of liquid will always remain therein impeding recycling of the inner tank.
In view of the foregoing limitations and shortcomings of the prior art devices, as well as other disadvantages not specifically mentioned above, it should be apparent that there still exists a need in the art for an improved foldable intermediate bulk container.
It is therefore a primary object of this invention to fulfill that need by providing a shipping container of the intermediate bulk container variety in which various components are connected to each other in a manner permitting folding into a flat, compact condition.
Another object of the present invention is to provide a foldable shipping container which, when folded, permits stacking in a stable manner and which compensates for any dimensional irregularities such that the folded container itself is provided with a compact, rectangular, generally box-like construction. A related object of this invention to provide a foldable shipping container which accommodates the differences in height of the side walls with respect to the length and width of the overall container so that, in its folded condition, none of the components of the IBC extend beyond the perimeter defined by its base.
Another object of this invention is to provide a mechanism which enhances the ability to fill the inner container of a shipping container.
It is also an object of this invention to provide an easily accessed pneumatically inflatable support structure within the inner tank of the shipping container which will increase the ease with which the inner tank can be filled and any air contained therein evacuated.
Another object of this invention is to provide a shipping container in which the end user is not required to install a valve assembly to the container at the site of use. A related object is to provide a shipping container in which the valve assembly is provided with the container and attached to the inner tank before shipment to the liquid supplier prior to filling of the inner container and shipping of the filled container to the end user.
Still another object of this invention is to provide a shipping container in which the valve assembly is protected during shipping and transporting of the container in either its folded or erected condition.